[BC] AM Stereo On A Mono Radio-FM Loudness

[RADIO DOCTOR]

On Fri, 5 Oct 2007, Mark Humphrey wrote:

> I also wonder if this could be interpreted to exclude the 19 kHz 
> stereo pilot from measurement.
>
> Consider that the pilot is added to the other components of a 
> composite waveform, and the period of each cycle is less than 1 
> millisecond.  If total modulation is set to 110% with a pilot 
> injection of 10% and you examine the instantaneous deviation of the 
> carrier on a scope, you'll see that the pilot "fuzz" (with these very 
> short peaks) is responsible for the portion of the waveform above 
> 100%, unless the pilot is being clipped.  Should we count them?

Turning the pilot on certainly makes a big difference in the amount of 
weighted peaks that can be ignored.  Very noticeable drop in apparent 
total modulation.

> I personally favor the occupied bandwidth approach, but it's more even 
> difficult to measure and interpret.

Yes, all my peak-weighted modultion monitor talk should not be 
interpreted to mean that I wouldn't like occupied bandwidth better. :)


...Lyle, FMeXtra evangelist, in Los Angeles, CA     Cell: 213-880-4690
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Lyle Henry, CPBE  THE RADIO DOCTOR  K9DKW/K7OO  Silver Lake/Los Angeles
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